Parking meters initially were coin operated. They were known to consist of a module to be fixed to a post having a lower end embedded in a ground surface typically adjacent a kerb adjacent which vehicles were to be parked. The parking meters were operated by inserting a coin and then turning a knob to activate a “clock” mechanism. When a certain period had expired, the parking meter would display a sign indicating the parking period had expired.
The above mentioned parking meters had a number of disadvantages including complexity of the working mechanisms, unreliability in respect of coins jamming and not being well adapted to provide a range of parking times and costs in respect thereof. A still further disadvantage is that they were restricted to coin operation.